GRAINEX: The Great Plains Irrigation Experiment

Summary

Land use land cover and subsequent changes (LULCC) play an important role in weather and climate systems. Observations and modeling studies suggest that LULCC impacts meso- regional, and potentially global-scale atmospheric circulations, temperature, precipitation, and fluxes. This research project plans to investigate the impacts of the rapid commencement irrigation and subsequent sustained irrigation on the evolution of planetary boundary layer atmosphere in a region of the Central Great Plains, specifically in Nebraska. We will determine the impacts of the rapid commencement of irrigation in the spring and resultant changes in the land-atmosphere (L-A) coupling at the mesoscale. In addition, this research will investigate the intra-seasonal changes in application in irrigation and their impacts on the boundary layer atmosphere and various processes and mechanisms involved in these changes. To fulfill the objective of this study we will collect field data in collaboration with the Lower Atmospheric Observation Facilities (LAOF) of the University Consortium for Atmospheric Research (UCAR) and conduct model simulations to further understand the impacts of irrigation on the atmosphere. To further understand land-atmosphere interactions and coupling, this study will use the Weather Research and Forecasting (WRF) model centered on southeastern Nebraska, a region containing strong soil moisture gradients due to widespread application of irrigation in certain areas.